A device corresponding to the preamble for dispensing cleaning or disinfection agents or the like is known from CH-A5-676 227. This design is based on production engineering adaptations to the designs in EP-A1-0 019 582 and EP-A1-0 079 853.
The foaming unit used here is also already known (CH-A5-676 456) and is most commonly used in the closures and dispensers fitted to bottles, usually plastic. Pressing the bottle walls causes liquid and air to be pressed into the "foamer" mounted on the bottle, where it is swirled, foamed, forced through a microfilter and dispensed directly at the nozzle as foam. In all the design forms, tolerances necessary for production engineering reasons are compensated by relative movement between the parts.
The known appliances are of relatively complicated construction (EP-A1-0 019 582 and EPA1-0 079 853) or leave something to be desired in their foam quality (CH-A5-676 227). The sizes of the individual foam portions differ with slow movements and quick movements of the lever; the valves and arrangements used tend to dribble. In addition, the air buffers in the metering pump, which are intended to ensure the ejection of the soap, have a negative effect on the constancy of the metered quantity.